Leviticus 9:1-8

On the eighth day Moses called Aaron and his sons and the elders of Israel, and he said to Aaron, “Take for yourself a bull calf for a sin offering and a ram for a burnt offering, both without blemish, and offer them before the LORD. And say to the people of Israel, ‘Take a male goat for a sin offering, and a calf and a lamb, both a year old without blemish, for a burnt offering, and an ox and a ram for peace offerings, to sacrifice before the LORD, and a grain offering mixed with oil, for today the LORD will appear to you.’” And they brought what Moses commanded in front of the tent of meeting, and all the congregation drew near and stood before the LORD. And Moses said, “This is the thing that the LORD commanded you to do, that the glory of the LORD may appear to you.” Then Moses said to Aaron, “Draw near to the altar and offer your sin offering and your burnt offering and make atonement for yourself and for the people, and bring the offering of the people and make atonement for them, as the LORD has commanded.” So Aaron drew near to the altar and killed the calf of the sin offering, which was for himself.